Abstract
People use motion information to locate moving objects in space, and they mislocalize objects when the background moves. But motion processing might also help locate stationary objects, given that people saw them moving before and regard movements as likely. This is predicted by an optimal inference model of transsaccadic integration that we have previously proposed. Here we show that the model applies to space perception outside the saccade as well. We asked participants to view objects from the corner of their eyes and to remember their location. Then we displaced the objects while modulating perception of displacements in two ways: (a) we displaced the objects either before or during saccades to examine the influence of saccadic suppression of motion; (b) we blanked displacements to degrade visual motion information. Also, blanking might make it more conceivable that a new object has appeared rather than the old one moved, thus altering expectations about displacements. As predicted by the model, blanked displacements outside the saccade biased localization towards the new location. In contrast, blanked displacements inside saccades were veridically perceived but displacements with no blank were misperceived, consistent with Deubel and colleagues' (1994) blanking effect. Our data support the idea that spatial perception integrates past motion information to process object locations.